(1) Field of the Invention
The present invention relates to an abnormality detection device, and more particularly to a device, method, system and executable program which are suitable for detecting an abnormality such as an unusual human activity which has occurred in an elderly person who lives alone in a house.
(2) Description of the Related Art
Various attempts have been made for detecting an abnormality which has occurred in an event such as the operation of a machine and human behavior. For example, it is an important technology, particularly in rapidly aging Japan, to monitor the activities of an elderly person who lives alone and to detect any occurrence of his unusual activity. One of such conventional technologies is “Abnormality Report System” which is disclosed in the Japanese Laid-Open Patent Application No. 2001-67576.
This conventional system includes, for monitoring the daily life of an elderly person or a sick person who lives alone, (a) a sensor unit which is placed in the restroom in the house of the person that is subject to monitoring and which outputs a predetermined signal when detecting the use of the restroom, (b) a first communication means (a wireless terminal device) which is placed in the restroom and which outputs a predetermined signal when receiving the signal from the sensor unit, and (c) a second communication means (a main device) which includes a monitoring timer that starts clocking when the signal is received from the first communication means and which reports the occurrence of an abnormality to the monitoring center when the signal from the first communication means is interrupted for a predetermined time period or more. When the elderly person faints due to a disease or the like and cannot move at all, he does not use the restroom for the predetermined time period or more, and thereby, it is detected that something abnormal has occurred in him.
However, the above-cited conventional system is based on his behavior characteristic that he always goes to the restroom within the predetermined time period. Therefore, steps are required to eliminate an exceptional case when the elderly person does not go to the restroom for the predetermined time period or more even in normal situations, such as when he goes out and he does his needs with a chamber pot.
Furthermore, since this conventional system only detects unusual human activities in a building with a restroom, there is a problem in that the uses and available opportunities thereof are extremely limited. In other words, the conventional system can detect neither unusual human activities in a place without a restroom or in a time period when the restroom is not used, nor abnormal motions of animals such as a pet or machines which do not use a restroom.